What are the "must have" jQuery plugins? [closed]

My list:

• Autocomplete
  • Input field to enable users quickly finding and selecting some value, leveraging searching and filtering.
• JSON
  • JSON plugin retrieving retrieving and manipulating json data.
• Cookie
  • Simple & lightweight utility plugin for reading, writing and deleting cookies.
• Vaildation
  • For validating form input data.
• UI
  • Full-featured themable and ready-to-use widgets and more...
• Interface
  • Dragging, Sortables, Droppables, plug-and-play components and visual effects.
• Cycle
  • Versatile and lightweight image slideshow plugin.

We currently use:

Most impressive

• Layout (dock, pin, splitter) - just amazing

Jquery UI elements:

• Tabs - tabbed UI
• AutoComplete - suggestion box from web service
• DatePicker - nice calendar date picker

Useful community plugins:

• Scrollable - scrolls any div
• Scrollpane - control scrollbar appearance
• Table sorter - table sorting (client-side) for any simple table
• QuickSearch - instant searching of table content
• Validate - form validation (required / type / custom regEx)
• HotKeys - traps for key shortcuts. Captures EVERY key on the keyboard. Awesome.
• BlockUI - awesome modal dialogs
• Curvy Corners - anti-aliased by default
• Tokenised input (or Facebook autocomplete with Xs) - Facebook style tokenised autocomplete

More to come, I'll add links etc...

I think that Flot plugin (a plotting library / plugin) deserves a place in this "must-have" list.

In addition, it is used here, in StackOverflow, to display the histogram of the reputation in the user account page.

I'll list one I'm working on...

My jLINQ plugin is a jQuery version of .NET LINQ. It's made for working with in-memory collections (not talking directly to the server) and let's you use syntax similar to the following.

var results = $.from(data)
    .ignoreCase()
    .startsWith("firstName","m")
    .or("n")
    .isNot("administrator")
    .orderBy("lastName")
    .select();

It supports a bunch of other commands that you find in LINQ for ordering and grouping along with most of the selection commands like contains, between, greaterThan, etc...

Here is a demo - It's stable, but still in progress

Maybe not must have, but might be useful as it progresses...